1. Field of the Invention
This invention relates to an image forming apparatus having a housing capable of cooling an object inside the housing by means of a cooling fan.
2. Description of the Related Art
In this field of art, there have been known various image forming apparatus, such as printers, copying machines, facsimiles, or multi-functional products in combination thereof, in which objects of a nature to generate heat are cooled by means of a cooling fan.
For example, a full color image forming apparatus includes a toner box for containing a black toner, a toner box for containing a cyan toner, a toner box for containing a yellow toner and a toner box for containing a magenta toner. Each of these four toner boxes generates heat upon toner stirring therein at the stirring blade or the bearing for the stirring shaft. Thus generated heat would damage the toner to lose its fluidity, which results in a failure in forming a desired color image.
For solving the above problem, Japanese Unexamined Patent Publication No. 2002-6697, for example, has proposed to introduce air taken-in by the cooling fan to each of the four toner boxes with corresponding number of air ducts to cool the boxes, respectively.
The above prior art, however, remains with a problem unsolved in that the toner boxes cannot be cooled if there is no space to provide the four ducts between the air exit of the cooling fan and each of the toner boxes.